My position on breaking up banks generates questions from two groups. Libertarians ask, how can I justify breaking up private sector institutions? Naive liberals ask, why is this policy not embraced by our political leaders?

My answer to both relates to what I call the Harvard-Goldman filter.

The Harvard-Goldman filter works like this.

1. To get into a position of power, you have to pass through a filter. The easiest way to show that you can pass through the filter is to go to Harvard and then work for Goldman.

2. If you do not go to Harvard and work for Goldman, then you have to show that you can get along with people who did.

3. The best way to show that you can get along with people who pass the Harvard-Goldman filter is to show that you believe in applying the Harvard-Goldman filter.

Why was Tim Geithner regarded as such an obvious, in fact necessary, choice to be Treasury Secretary? Because he satisfies the Harvard-Goldman filter, particularly point (3). He is not going to bring people from the wrong social caste into the policymaking arena.

A point that I keep making about higher education is that it is, like the Harvard-Goldman filter, a form of recursive credentialism. To get certain jobs, you need certain credentials. And the most important credential of all is that you must signal your support for credentialism.